Pluggables vs CPO 的 InP 用量
Pluggable 光模組實際使用的 InP 遠多於 CPO(共封裝光學)。
市場把 InP 題材跟 CPO 綁在一起,主要是因為雷射品質與穩定性要求極高,只有很小比例能通過認證,等於放大了 InP 需求。
對 CPO / NPO 的看法偏空
• 不看好 CPO 或 NPO 大規模普及。
• 預計 switch 相關應用至少還要 3 年才可能廣泛採用。
• CPO 在 scale-up 的功耗效率其實比銅線更差(因為需要 thermal tuning),這點很意外,因為功耗優勢原本是採用 CPO 的主要理由。
其他技術路徑
• VCSEL 看起來更有潛力,而且完全不含 InP。雖然還有不少缺點,但修正難度可能低於 CPO。
• 更好的晶片封裝技術會降低對高速網路的壓力。
• Inference(推理)架構對頻寬要求沒有訓練那麼高,可能用簡單的 25G 互連就夠。
結論
直接或間接做多 InP 供應鏈,需要很多假設很快成真。對此持保留態度。
更看好 microLED。
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Interesting facts I learned today
Pluggables actually use much more InP than CPO. The reason the InP trade was always associated with CPO is that the laser quality and stability is so high it’s like a double bottleneck where a small % of them can get qualified for use thus it greatly multiplies the demand for InP more than normal.
Thus I see this “shortage” as extremely levered to CPO working despite having less InP content. I’m not bullish on CPO or NPO for scale up at all and even when it comes to switches and I don’t think those will be widespread for another 3 years at best. Even worst CPO is actually WORST than copper for scale up when it comes to power efficiency because of thermal tuning !!! I found this to be really shocking since that was the only real reason to use it for scale up in the first place.
VCSELs seem more promising and don’t have any InP content at all. It’s too early to say if they win as there are many drawbacks but much easier to fix than CPO imo. Then we have the added fact that better chip packaging lowers pressure on networking (or at least keeps it the same) and the added fact that for inference architectures you probably can get away with just a simple 25G interconnect since bandwidth isn’t stressed as much as training.
With all this being said, why would you be long the InP supply chain directly or indirectly? Seems like a lot of assumptions baked in that are going to need to become reality fast.
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